A symbol or name that stands for a value. For example, in the expression

x+y

x and y are variables. Variables can represent numeric values, characters, character strings, or memory addresses.

Variables play an important role in computer programming because they enable programmers to write flexible programs. Rather than entering data directly into a program, a programmer can use variables to represent the data. Then, when the program is executed, the variables are replaced with real data. This makes it possible for the same program to process different sets of data.

Every variable has a name, called the variable name, and a data type. A variable's data type indicates what sort of value the variable represents, such as whether it is an integer, a floating-point number, or a character.

The opposite of a variable is a constant. Constants are values that never change. Because of their inflexibility, constants are used less often than variables in programming.

The fundamental types are these four

* Integers (both signed and unsigned) 1,2,4 or 8 bytes in size. Usually referred to as ints.
* Floating Point Numbers up to 8 bytes in size.
* Bytes. These are organised in 4s or 8s (32 or 64 bits) and read in and out of the CPU's registers.
* Text strings, up to billions of bytes in size. CPUs have special instructions for searching through large blocks of bytes in memory. This is very handy for text operations.

Answered by R.P. Singh , an ibibo Master, at 6:44 PM on July 22, 2008

A symbol or name that stands for a value. For example, in the expression

x+y

x and y are variables. Variables can represent numeric values, characters, character strings, or memory addresses.

Variables play an important role in computer programming because they enable programmers to write flexible programs. Rather than entering data directly into a program, a programmer can use variables to represent the data. Then, when the program is executed, the variables are replaced with real data. This makes it possible for the same program to process different sets of data.

Every variable has a name, called the variable name, and a data type. A variable's data type indicates what sort of value the variable represents, such as whether it is an integer, a floating-point number, or a character.

The opposite of a variable is a constant. Constants are values that never change. Because of their inflexibility, constants are used less often than variables in programming.

The fundamental types are these four

* Integers (both signed and unsigned) 1,2,4 or 8 bytes in size. Usually referred to as ints.
* Floating Point Numbers up to 8 bytes in size.
* Bytes. These are organised in 4s or 8s (32 or 64 bits) and read in and out of the CPU's registers.
* Text strings, up to billions of bytes in size. CPUs have special instructions for searching through large blocks of bytes in memory. This is very handy for text operations.

Answered by Raksha , an ibibo Master, at 10:42 PM on July 20, 2008

A symbol or name that stands for a value. For example, in the expression

x+y

x and y are variables. Variables can represent numeric values, characters, character strings, or memory addresses.

Variables play an important role in computer programming because they enable programmers to write flexible programs. Rather than entering data directly into a program, a programmer can use variables to represent the data. Then, when the program is executed, the variables are replaced with real data. This makes it possible for the same program to process different sets of data.

Every variable has a name, called the variable name, and a data type. A variable's data type indicates what sort of value the variable represents, such as whether it is an integer, a floating-point number, or a character.

The opposite of a variable is a constant. Constants are values that never change. Because of their inflexibility, constants are used less often than variables in programming.

The fundamental types are these four

* Integers (both signed and unsigned) 1,2,4 or 8 bytes in size. Usually referred to as ints.
* Floating Point Numbers up to 8 bytes in size.
* Bytes. These are organised in 4s or 8s (32 or 64 bits) and read in and out of the CPU's registers.
* Text strings, up to billions of bytes in size. CPUs have special instructions for searching through large blocks of bytes in memory. This is very handy for text operations.

Answered by Rocky , an ibibo Master, at 8:39 PM on July 19, 2008

A symbol or name that stands for a value. For example, in the expression

x+y

x and y are variables. Variables can represent numeric values, characters, character strings, or memory addresses.

Variables play an important role in computer programming because they enable programmers to write flexible programs. Rather than entering data directly into a program, a programmer can use variables to represent the data. Then, when the program is executed, the variables are replaced with real data. This makes it possible for the same program to process different sets of data.

Every variable has a name, called the variable name, and a data type. A variable's data type indicates what sort of value the variable represents, such as whether it is an integer, a floating-point number, or a character.

The opposite of a variable is a constant. Constants are values that never change. Because of their inflexibility, constants are used less often than variables in programming.

The fundamental types are these four

* Integers (both signed and unsigned) 1,2,4 or 8 bytes in size. Usually referred to as ints.
* Floating Point Numbers up to 8 bytes in size.
* Bytes. These are organised in 4s or 8s (32 or 64 bits) and read in and out of the CPU's registers.
* Text strings, up to billions of bytes in size. CPUs have special instructions for searching through large blocks of bytes in memory. This is very handy for text operations.

Answered by Santosh Kuma , an ibibo Master, at 2:11 PM on July 18, 2008

A symbol or name that stands for a value. For example, in the expression

x+y

x and y are variables. Variables can represent numeric values, characters, character strings, or memory addresses.

Variables play an important role in computer programming because they enable programmers to write flexible programs. Rather than entering data directly into a program, a programmer can use variables to represent the data. Then, when the program is executed, the variables are replaced with real data. This makes it possible for the same program to process different sets of data.

Every variable has a name, called the variable name, and a data type. A variable's data type indicates what sort of value the variable represents, such as whether it is an integer, a floating-point number, or a character.

The opposite of a variable is a constant. Constants are values that never change. Because of their inflexibility, constants are used less often than variables in programming.

The fundamental types are these four

* Integers (both signed and unsigned) 1,2,4 or 8 bytes in size. Usually referred to as ints.
* Floating Point Numbers up to 8 bytes in size.
* Bytes. These are organised in 4s or 8s (32 or 64 bits) and read in and out of the CPU's registers.
* Text strings, up to billions of bytes in size. CPUs have special instructions for searching through large blocks of bytes in memory. This is very handy for text operations.

Answered by Ashish Yadav , an ibibo Wizard, at 2:10 PM on July 16, 2008

well, A symbol or name that stands for a value. For example, in the expression

x+y

x and y are variables. Variables can represent numeric values, characters, character strings, or memory addresses.

Variables play an important role in computer programming because they enable programmers to write flexible programs. Rather than entering data directly into a program, a programmer can use variables to represent the data. Then, when the program is executed, the variables are replaced with real data. This makes it possible for the same program to process different sets of data.

Every variable has a name, called the variable name, and a data type. A variable's data type indicates what sort of value the variable represents, such as whether it is an integer, a floating-point number, or a character.

The opposite of a variable is a constant. Constants are values that never change. Because of their inflexibility, constants are used less often than variables in programming.

The fundamental types are these four

* Integers (both signed and unsigned) 1,2,4 or 8 bytes in size. Usually referred to as ints.
* Floating Point Numbers up to 8 bytes in size.
* Bytes. These are organised in 4s or 8s (32 or 64 bits) and read in and out of the CPU's registers.
* Text strings, up to billions of bytes in size. CPUs have special instructions for searching through large blocks of bytes in memory. This is very handy for text operations.

Answered by .... ..... , an ibibo Master, at 11:17 AM on July 16, 2008

A variable is a place to store a piece of information. Just as you might store a friend's phone number in your own memory, you can store this information in a computer's memory. Variables are your way of accessing your computer's memory. Of course, your memory changes over time. Your friend moves across country and has a new phone number, and your friend's new phone number will replace the old one in your memory. Over time, as you acquire new friends, your memory will keep changing to store different pieces of information. Likewise, a computer's memory can change over time, if you tell it to. Since variables are your access point to your computer's memory, it makes sense that you'd be able to change the information in a computer's memory; otherwise, they wouldn't be called variables (they'd be called statics).
Why should you care about variables? Variables are the essence of any computer program! Without variables, computers would be useless. Imagine a program which asks the user for two numbers and adds them together, and prints the result.
# AddTwoNumbers
Enter the first number: 2
Enter the second number: 5
The sum of 2 and 5 is 7.
#
Sounds simple, right? But let's do a little role-playing to see what the computer has to do to execute this program. Instead of this interaction between a person and a computer, let's imagine the same kind of conversation between two people, Sol and Frank.
Sol: Hey Frank, I just learned how to add two numbers together.
Frank: Cool!
Sol: Give me the first number.
Frank: 2.
Sol: Ok, and give me the second number.
Frank: 5.
Sol: Ok, here's the answer: 2 + 5 = 7.
Frank: Sheesh! This guy is unbelievable!
After Frank says "2", Sol has to store that number in his memory somewhere. It may be stored in short-term memory, but he has to store it somewhere before Frank gives him the second number. Even if Frank were to give him two numbers in the same sentence, Sol would have to store the numbers somewhere in his memory to add them together.
In the sample program described above, the computer would most likely store "2" in a variable, then store "5" in a variable, and then calculate the sum by calculating the sum of the numbers store in the two variables.
Although there are similarities between a person's memory and a computer's memory, there are some pretty big differences. In C++, you need to grab a little piece of the computer's memory before you can use it. In other words, you have to tell the computer that you're planning to store a number in a variable before you can actually do it. This is called declaring a variable. To declare a variable, you need to know what kind of information it will store (i.e., will it store a number, or a text-string, or something else) and how you plan to refer to the variable (i.e., the variable's name). C++ imposes fairly strict rules on how you can name your variables:

Answered by Ni .. , an ibibo Master, at 7:26 PM on July 15, 2008

well, A symbol or name that stands for a value. For example, in the expression

x+y

x and y are variables. Variables can represent numeric values, characters, character strings, or memory addresses.

Variables play an important role in computer programming because they enable programmers to write flexible programs. Rather than entering data directly into a program, a programmer can use variables to represent the data. Then, when the program is executed, the variables are replaced with real data. This makes it possible for the same program to process different sets of data.

Every variable has a name, called the variable name, and a data type. A variable's data type indicates what sort of value the variable represents, such as whether it is an integer, a floating-point number, or a character.

The opposite of a variable is a constant. Constants are values that never change. Because of their inflexibility, constants are used less often than variables in programming.

The fundamental types are these four

* Integers (both signed and unsigned) 1,2,4 or 8 bytes in size. Usually referred to as ints.
* Floating Point Numbers up to 8 bytes in size.
* Bytes. These are organised in 4s or 8s (32 or 64 bits) and read in and out of the CPU's registers.
* Text strings, up to billions of bytes in size. CPUs have special instructions for searching through large blocks of bytes in memory. This is very handy for text operations.

Answered by Romi , an ibibo Master, at 11:30 AM on July 08, 2008

programming is nothing but processing data. data plays main role in programming. so we have to store that data while we are processing data. variable is nothing but memory point. we store particular data type by declaring variable like integer,string or float.

Answered by Praveen , an ibibo Citizen, at 5:09 PM on June 28, 2008

A variable is a place to store a piece of information. Just as you might store a friend's phone number in your own memory, you can store this information in a computer's memory. Variables are your way of accessing your computer's memory. Of course, your memory changes over time. Your friend moves across country and has a new phone number, and your friend's new phone number will replace the old one in your memory. Over time, as you acquire new friends, your memory will keep changing to store different pieces of information. Likewise, a computer's memory can change over time, if you tell it to. Since variables are your access point to your computer's memory, it makes sense that you'd be able to change the information in a computer's memory; otherwise, they wouldn't be called variables (they'd be called statics).
Why should you care about variables? Variables are the essence of any computer program! Without variables, computers would be useless. Imagine a program which asks the user for two numbers and adds them together, and prints the result.
# AddTwoNumbers
Enter the first number: 2
Enter the second number: 5
The sum of 2 and 5 is 7.
#
Sounds simple, right? But let's do a little role-playing to see what the computer has to do to execute this program. Instead of this interaction between a person and a computer, let's imagine the same kind of conversation between two people, Sol and Frank.
Sol: Hey Frank, I just learned how to add two numbers together.
Frank: Cool!
Sol: Give me the first number.
Frank: 2.
Sol: Ok, and give me the second number.
Frank: 5.
Sol: Ok, here's the answer: 2 + 5 = 7.
Frank: Sheesh! This guy is unbelievable!
After Frank says "2", Sol has to store that number in his memory somewhere. It may be stored in short-term memory, but he has to store it somewhere before Frank gives him the second number. Even if Frank were to give him two numbers in the same sentence, Sol would have to store the numbers somewhere in his memory to add them together.
In the sample program described above, the computer would most likely store "2" in a variable, then store "5" in a variable, and then calculate the sum by calculating the sum of the numbers store in the two variables.
Although there are similarities between a person's memory and a computer's memory, there are some pretty big differences. In C++, you need to grab a little piece of the computer's memory before you can use it. In other words, you have to tell the computer that you're planning to store a number in a variable before you can actually do it. This is called declaring a variable. To declare a variable, you need to know what kind of information it will store (i.e., will it store a number, or a text-string, or something else) and how you plan to refer to the variable (i.e., the variable's name). C++ imposes fairly strict rules on how you can name your variables:
* variable names must begin with a letter
* variable names are "case-sensitive" (i.e., the variable "myNumber" is different from the variable "MYNUMBER" which is different from the variable "mYnUmBeR")
* variable names can't have spaces
* variable names can't have special characters (typographic symbols)
What can you name your variables? In general, variable names can be composed of letters, numbers, and underscores (_). However, C++ reserves certain keywords which have special meaning to the language, and you are not allowed to use any of these keywords as variables names. Some examples of C++ keywords are int, for, else, and class. You can, however, use keywords in the middle of a variable name, such as "foreign" or "classical".
for more information;
http://cplus.abo ut.co m/od/introductiontoprogramming /p/va riable.htm

Answered by Shobhit , an ibibo Master, at 6:39 PM on June 27, 2008